Flower design is a vast subject and includes both formal versions and informal versions. In the dahlia shows there are generally a team of official garden club judges and dahlia judges in a dahlia show. The garden club judges use their rules that have evolved for many decades and are quite detailed and it takes many years to become a garden club judge.
In the now almost extinct florist industry, there used to be hundreds of thousands if not millions of small independent florist shops nearly everywhere. Floral design was an occupation and florists were very skilled at producing floral designs for special occasions. And they delivered too and a nice part time job was delivering for a florist.
In 1967, during the Valentines day mad rush to deliver flowers, I was in college and had a car and for one day I delivered valentine flowers in Portland for "Flowers by Tommy Luke" . I remember nothing of the recipients or the flowers and only that finding all those addresses with a crude map was a real challenge.
There are no longer very many florist shops operated by individuals. The world has changed.
Another area that impacts the dahlia world is that the wholesale providers of floral supplies have also been closing. In the past , you could go to the wholesale florist supply and buy all of your floral needs from floral wire to floral baskets, to thousands of different vases,, and anything related to the floral industry, an acre or two of florist stuff.
Where do you buy that stuff now? On line is one source and one acquaintance said she buys her supplies at Safeway in the floral department as she used to work there and knows the staff.
This design was not done by Margaret.